1. Chapter 1 Introduction: Matter and Measurement
Lecture Presentation
Chapter 1 Introduction: Matter and Measurement
John D. Bookstaver
St. Charles Community College
Cottleville, MO

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Chemistry
Chemistry:
is the study of properties of materials and changes that they undergo.
can be applied to all aspects of life (e.g., development of pharmaceuticals, leaf color change in fall, etc.).
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Matter
matter - anything that has mass and takes up space
It is the physical material of the universe.
Property- any characteristic that allows us to recognize a particular type of matter and to distinguish it from other types of matter.
About 100 elements constitute all matter.
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Matter
Atoms are the building blocks of matter.
Each element is made of the same kind of atom.
A compound is made of two or more different kinds of elements.
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Elements
The building blocks of matter
Are made up of unique atoms.
Names of the elements are derived from a wide variety of sources (e.g., Latin or Greek, mythological characters, names of people or places).
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Elements
There are 117 known elements.
They vary in abundance.
Oxygen, silicon, aluminum, iron, and calcium make up over 90% of the Earth’s crust (including oceans and atmosphere).
Oxygen, carbon, and hydrogen make up over 90% of mass of the human body.
Each is given a unique name and is abbreviated by a chemical symbol.
They are organized in the periodic table.
Each is given a one- or two-letter symbol derived from its name.
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Molecules
Molecules are combinations of atoms held together in specific shapes.
Properties relate to composition (types of atoms present) and structure (arrangement of atoms) present.
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Compounds
Compounds are combinations of elements.
Example: The compound H2O is a combination of elements H and O.
The opposite of compound formation is decomposition.
Compounds have different properties than their component elements (e.g., water is liquid, hydrogen and oxygen are both gases at the same temperature and pressure).
Law of Constant Composition or the Law of Constant (Definite) Proportions
compound always consists of the same combination of elements (e.g., water is always 11% H and 89% O).
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Why Study Chemistry?
it has a considerable impact on society (health care, food, clothing, conservation of natural resources, environmental issues, etc.).
it is part of your curriculum! Chemistry serves biology, engineering, agriculture, geology, physics, etc..
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10. 1.2 Classification of Matter: States of Matter
Solids, liquids and gases are the three forms of matter called the states of matter.
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Properties that describe the states of matter at the macroscopic level:
gas (vapor): no fixed volume or shape, conforms to shape of container, compressible.
liquid: volume independent of container, no fixed shape, incompressible.
solid: volume and shape independent of container, rigid, incompressible.
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Properties that describe the states of matter at the microscopic level:
gas: molecules far apart, move at high speeds, collide often.
liquid: molecules closer than gas, move rapidly but can slide over each other.
solid: molecules packed closely in definite arrangements.
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Pure Substances
are matter with distinct properties and fixed composition.
A sample of matter with both definite and constant composition with distinct chemical properties.
Any single type of material.
Pure Substances are elements
cannot be decomposed into simpler substances
only one kind of atom
or compounds
(consist of two or more elements).
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Mixtures
are a combination of two or more pure substances.
Each substance retains its own identity.
Each substance is a component of the mixture
Mixtures have variable composition
Heterogeneous mixtures do not have uniform composition, properties and appearance, e.g., sand.
Homogeneous mixtures are uniform throughout, e.g., clean air or vinegar; they are solutions.
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15. Classification of Matter
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16. Classification of Matter
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17. Classification of Matter
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18. Classification of Matter
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19. Classification of Matter
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20. Classification of Matter
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21. Classification of Matter
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22. Classification of Matter
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23. Classification of Matter
And
Measurement
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24. Classification of Matter
And
Measurement
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25. Properties and Changes of Matter
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Types of Properties
Each substance has a unique set of physical and chemical properties
Physical Properties…
-Can be observed without changing a substance into another substance.
Boiling point, density, mass, volume, color, mass, etc.
Chemical Properties
Can only be observed when a substance reacts to change into another substance.
Flammability, corrosiveness, reactivity with acid, etc.
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Types of Properties
Intensive Properties
Are independent of the amount of the substance that is present.
Density, boiling point, color, etc.
Extensive Properties
Depend upon the amount of the substance present.
Mass, volume, energy, etc.
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Types of Changes
Physical Changes
These are changes in matter that do not change the composition of a substance.
substance changes physical appearance without altering its identity
Changes of state, temperature, volume, etc.
Chemical Changes
Chemical changes result in new substances.
Combustion, oxidation, decomposition, etc.
i.e. identity changes, e.g., reaction of hydrogen and oxygen gases to produce water.
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Chemical Reactions
In the course of a chemical reaction, the reacting substances are converted to new substances.
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30. Separation of Mixtures
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31. Separation of Mixtures
Filtration: remove solid from liquid.
Distillation: boil off one or more components of the mixture.
Chromatography: exploits differing abilities of substances to adhere to the surfaces of solids.
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Filtration
In filtration, solid substances are separated from liquids and solutions.
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Distillation
Distillation uses differences in the boiling points of substances to separate a homogeneous mixture into its components.
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Chromatography
This technique separates substances on the basis of differences in solubility in a solvent.
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The Scientific Method
provides guidelines for the practice of science.
Collect data (observe, experiment, etc.).
Look for patterns, try to explain them and develop a hypothesis or tentative explanation.
Test hypothesis, then refine it.
Bring all information together into a scientific law (concise statement or equation that summarizes tested hypotheses).
Bring hypotheses and laws together into a theory. A theory should explain general principles.
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Units of Measurement
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SI Units
Système International d’Unités
A different base unit is used for each quantity.
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Metric System
Prefixes convert the base units into units that are appropriate for the item being measured.
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Volume
The most commonly used metric units for volume are the liter (L) and the milliliter (mL).
A liter is a cube 1 decimeter (dm) long on each side.
A milliliter is a cube 1 centimeter (cm) long on each side.
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Temperature
By definition temperature is a measure of the average kinetic energy of the particles in a sample.
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Temperature
In scientific measurements, the Celsius and Kelvin scales are most often used.
The Celsius scale is based on the properties of water.
0 C is the freezing point of water.
100 C is the boiling point of water.
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Temperature
The kelvin is the SI unit of temperature.
It is based on the properties of gases.
There are no negative Kelvin temperatures.
K = C
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Temperature
The Fahrenheit scale is not used in scientific measurements.
F = 9/5(C) + 32
C = 5/9(F − 32)
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Derived Units
Density is a physical property of a substance.
It has units (g/mL, for example) that are derived from the units for mass and volume.
d = m V
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45. Uncertainty in Measurement
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46. Uncertainty in Measurements
Different measuring devices have different uses and different degrees of accuracy.
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Significant Figures
The term significant figures refers to digits that were measured.
When rounding calculated numbers, we pay attention to significant figures so we do not overstate the accuracy of our answers.
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Significant Figures
All nonzero digits are significant.
Zeroes between two significant figures are themselves significant.
Zeroes at the beginning of a number are never significant.
Zeroes at the end of a number are significant if a decimal point is written in the number.
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Significant Figures
When addition or subtraction is performed, answers are rounded to the least significant decimal place.
When multiplication or division is performed, answers are rounded to the number of digits that corresponds to the least number of significant figures in any of the numbers used in the calculation.
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50. Accuracy versus Precision
Accuracy refers to the proximity of a measurement to the true value of a quantity.
Precision refers to the proximity of several measurements to each other.
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Dimensional Analysis
We use dimensional analysis to convert one quantity to another.
Most commonly, dimensional analysis utilizes conversion factors (e.g., 1 in. = 2.54 cm)
1 in.
2.54 cm or
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Dimensional Analysis
Use the form of the conversion factor that puts the sought-for unit in the numerator:
Given unit 
 desired unit
desired unit
given unit
Conversion factor
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Dimensional Analysis
For example, to convert 8.00 m to inches,
convert m to cm
convert cm to in.
8.00 m 
100 cm
1 m
1 in.
2.54 cm 
315 in. 
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